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Research interests

My interests cover a range of topics which normally can be grouped under the heading 'cell signalling systems in invertebrates' and I tend to approach research questions from the perspective of a biochemist/cell biologist.

Most recently, I have been interested in how phagocytosis contributes to cell-mediated immunity, using a model insect, Manduca sexta. We have been examining phagocytosis of bacteria in vitro with a view to understanding the cellular and biochemical mechanisms by which the phenomenon is initiated and regulated.

Research projects

Signal transduction systems in insect haemocytes

  • Responses of insect haemocytes to immunostimulants and peptide hormones are being characterised using fluorescence imaging of second messenger responses (primarily calcium imaging). Together with results of complementary methods, including immunocytochemistry and in situ hybridisation, the work will reveal signalling pathways underlying changes in haemocyte behaviour and cellular physiology in response to primary signalling events. A present focus is on regulation of phagocytosis of bacteria and other insect pathogens by insect haemocytes. This work has been initiated by Patricia de Winter, who recently completed her PhD with me and Dr Geoff Coast as co-supervisors.
  • Exciting new avenues in this area (and others) will open up when we obtain a confocal microscope system here at Birkbeck (via SRIF), as we will be able to take a more “cell biological” approach to the work. In time it may be possible to initiate studies of processes in cell-mediated immunity in Drosophila using imaging approaches; this would be novel work and would enable application of genetic approaches to understand cellular functioning in an invertebrate immune system.

Roles for nitric oxide in invertebrate immunity

  • Previously, I have identified and partially characterised nitric oxide synthases in the haemocytes of several insects and crustaceans. This line of work has been revived after a long hiatus. Studies are underway to determine the role of the nitric oxide produced and to explain the regulation of its production. At present I and an MSc project student are exploring roles for NO in immunity in the insect Manduca sexta and the crustacean (crab) Carcinus maenas. This work will benefit from collaboration with Dr Valerie Smith at St Andrews University (one of the leading researchers on invertebrate immunity). This work is a logical adjunct to that described above and the two lines of research may merge in future.

Novel molecular targets for nitric oxide

  • This is a new area of research that will exploit a recently developed method to determine S-nitrosylation of proteins in nitric oxide target tissues (e.g. brain, haemocytes). Proteomic approaches will allow these proteins to be identified. The identity of the modified proteins will provide clues to the molecular pathways of action of nitric oxide in the particular physiological system being studied (e.g. nervous and immune systems).